The disclosure relates generally to hot gas path components for turbine systems, and more particularly, to hot gas path components formed as airfoils that include a plurality of nozzles and venturi formed therein.
Conventional turbomachines, such as gas turbine systems, generate power for electric generators. In general, gas turbine systems generate power by passing a fluid (e.g., hot gas) through a turbine component of the gas turbine system. More specifically, inlet air may be drawn into a compressor to be compressed. Once compressed, the inlet air is mixed with fuel to form a combustion product, which may be reacted by a combustor of the gas turbine system to form the operational fluid (e.g., hot gas) of the gas turbine system. The fluid may then flow through a fluid flow path for rotating a plurality of rotating blades and rotor or shaft of the turbine component for generating the power. The fluid may be directed through the turbine component via the plurality of rotating blades and a plurality of stationary nozzles or vanes positioned between the rotating blades. As the plurality of rotating blades rotate the rotor of the gas turbine system, a generator, coupled to the rotor, may generate power from the rotation of the rotor.
During operation, turbine blades and vanes, and more specifically the airfoils of each, may be exposed to high temperature operational fluids flowing through the flow path of the turbine component. Over time and/or during exposure, the airfoils of the turbine blades and vanes may undergo undesirable thermal expansion and/or operational wear. The thermal expansion of the airfoils may result in damage to and/or outages of the blades/vanes of the turbine. When the airfoils become damaged or undergo an outage event, the operational efficiency of the turbine component, and in turn the entire turbine system, may be reduced. Additionally, when an airfoil is damaged or an outage event occurs, the turbine component may need to shutdown to replace the damaged turbine blade and/or vane, resulting in no power being generated by the turbine system when the blade/vane is replaced.
To minimize thermal expansion and degradation, airfoils are typically cooled. For example, conventional airfoils typically contain an intricate maze of internal cooling passages. Cooling air (or other suitable coolant) provided by, for example, a compressor of a gas turbine system, may be passed through and out of the cooling passages to cool various portions of the airfoil for the blades and vanes. Cooling circuits formed by one or more cooling passages in these conventional airfoils may include, for example, internal, near wall cooling circuits, internal central cooling circuits, tip cooling circuits, and cooling circuits adjacent the leading and trailing edges of the airfoil.
Typically in conventional systems, only high pressure cooling air may be provided to and utilized by the airfoils for cooling. As a result, substantially all or most of the cooling air flowing through conventional gas turbine static components must be provided from high-pressure sources, which are subject to a greater quantity of compressor pumping work. Cooling air from lower-pressure sources that may otherwise be available to cool the components cannot be used if the pressure is too low. This in turn may reduce the operational efficiency of the gas turbine system, and/or may require supplemental high pressure air generation system(s) to be incorporated within the gas turbine system. Using supplemental high pressure air generation systems to provide additional high pressure air to the system thus add undesirable build, installation, maintenance, and/or operational expenses to the gas turbine system.